The present invention generally relates to a new and unique construction and configuration for a structure for encompassing a automatically resetting indicator fuse. More specifically, the invention relates to a fuse structure for enclosing the fuse circuit pack disclosed in the co-pending application of Knollman et al., Ser. No. 07/469,646. Additionally, new and improved fuse circuits are provided.
The construction of indicator or automatically resetting fuses is well known in the relevant art. Such fuses are usually enclosed in a cylindrical, cartridge-type housing. The housing is usually composed of a strong paper product rolled into a cylinder. The rolling process is time consuming, and can be quite tedious.
A first electrical contact and a second electrical contact are disposed on opposite ends of the housing, and are preferably crimped to the housing in order to prevent their motion independent of the housing. The electrical contacts are electrically connected to a fuse circuit by a plurality of wires. However, the housing provides no guides for these wires, and accordingly, the wires may become damaged during the fuse assembly process.
The second electrical contact is connected to an electrically conducting spring Thus, the spring becomes a mere electrical extension of the second electrical contact. An end of the electrically conducting spring opposite to the end thereof connected to the second electrical contact terminates at a third electrical contact which is engagable with an alarm element.
Additionally, a fusible element extends axially within the spring from the second electrical contact to the third electrical contact. If the electrically conducting spring is stretched too far, the fusible element will rupture, thereby rendering the fuse inoperative. Thus, there are many drawbacks to using the indicator fuses of the prior art. The present invention is directed towards removing those drawbacks, and providing an improved fuse structure construction.